Test Cases Library of Power System Sustained Oscillations

Simulated cases of oscillatory events(Back to the homepage)

     ➤Power system model

The power flow and dynamic files of all cases can be downloaded as one package using the link below. For forced oscillation cases, the dynamic files for modelling the external forces and their block diagrams are also included in the package. With the model, users can easily modify the parameters of their interests and design their own cases.

[DOWNLOAD]All Models (676KB)

Instructions:

     ➤Simulated PMU measurements

The simulated data from all cases can be downloaded from the links below. With these measurement data, users can directly load them into their program and run their location algorithm without dealing with models or simulations.

[DOWNLOAD] All in one (168MB)   or    Cases 1ND to 3ND (18MB)    Cases 4ND to 6ND (18MB)    Cases 7ND to 9ND (18MB)    Cases 1F to 3F (18MB)    Cases 4F1 to 4F3 (18MB)    Cases 5F1 to 5F3 (18MB)    Cases 6F1 to 6F3 (18MB)    Cases 7F1 to 7F2 (12MB)    Cases 1FM to 7FM1 (25MB)

Instructions:

     ➤Approach for generation of test cases

     ➤Summary of natural oscillation cases (Click case # for details)

Case # D Frequency/Hz Damping Source location Fault location Description
ND_1 D45=-2
D159=1		 1.41 0.01% 45 159 Single source - single local mode
ND_2 D35=0.5
D65=-1.5		 0.37 0.02% 65 79 Single source - single inter-area mode
ND_3 D6=2
D11=-6		 0.46
0.70
1.63		 2.22%
1.15%
-0.54%		 11 30 Single source - one unstable local mode and two poorly damped inter-area modes
ND_4 D6=5
D11=-9		 0.46
0.70
1.63		 0.68%
-0.58%
0.54%		 11 6 Single source - one unstable inter-area mode and two poorly damped local and inter-area modes
ND_5 D6=3
D11=-8		 0.46
0.70
1.63		 0.69%
-0.19%
-0.48%		 11 30 Single source - two unstable local and inter-area modes, and one poorly damped inter-area mode
ND_6 D45=-2
D159=-0.5		 1.41 -0.93% 45&159 159 Two sources with comparable contribution into a single unstable local mode
ND_7 D45=-0.5
D159=-0.5		 1.41 -0.40% 45&159 159 Two sources with different contributions into a single unstable local mode
ND_8 D45=-2.5
D159=1
D36=-1		 1.27
1.41		 -1.06%
-0.22%		 45&36 159 Two sources - two unstable local modes
ND_9 D11=-10 0.46
0.69
1.63		 -0.86%
-1.81%
-0.40%		 11 79 Single source - three unstable modes
  • "ND" means negative damping. For simplicity, it is used here to represent cases with poorly damped oscillations, undamped oscillations or negative-damping oscillations.

    • The default value of damping coefficient D for all generators is 4. In each case, any deviations from the default values are shown in the second column of the above table. The source of oscillations is the generator with negative D value.

    Eigenanalysis results for the above cases are here (Eigenanalysis ND.xls).

    As an example, here are the details of the cases ND_1, ND_4, and ND_6 and ND_7.

         ➤Summary of forced oscillation cases (Click case # for details)

    Case # Type of injected signal Frequency of first harmonic/Hz Source location Description
    F_1 Sinusoidal 0.86 4 Resonance with local 0.86Hz mode
    F_2 Sinusoidal 0.86 79 Resonance with local 0.86Hz mode
    F_3 Sinusoidal 0.37 77 Resonance with inter-area 0.37Hz mode
    F_4_1 Sinusoidal 0.81 79 Forcing frequency is below natural 0.84Hz mode
    F_4_2 Sinusoidal 0.85 79 Forcing frequency is between natural 0.84Hz and 0.86Hz modes
    F_4_3 Sinusoidal 0.89 79 Forcing frequency is higher than natural 0.86Hz mode
    F_5_1 Sinusoidal 0.42 79 Forcing frequency is below natural 0.44Hz inter-area mode
    F_5_2 Sinusoidal 0.46 79 Forcing frequency is between natural 0.44Hz and 0.47Hz inter-area modes
    F_5_3 Sinusoidal 0.50 79 Forcing frequency is higher than natural 0.47Hz inter-area mode
    F_6_1 Periodic, rectangular 0.1 79 Spectra of forced harmonics consist of 0.1Hz, 0.3Hz, 0.5Hz, 0.7Hz, etc modes
    F_6_2 Periodic, rectangular 0.2 79 Spectra of forced harmonics consist of 0.2Hz, 0.6Hz, 1Hz, 1.4Hz, etc modes
    F_6_3 Periodic, rectangular 0.4 79 Spectra of forced harmonics consist of 0.4Hz, 1.2Hz, 2Hz, etc modes
    F_7_1 Sinusoidal 0.65
    0.43    		 79
    118    		 Two sources of forced signals creating resonance with two different modes, respectively
    F_7_2 Sinusoidal 0.43 70
    118    		 Two sources of forced signals creating resonance with the same mode

    Each case of forced oscillations has only one generator with periodic signal injected into its excitation system. The presence of the excitation system to one generator only slightly changes the parameters of oscillations (Eigenanalysis Forced.xls) comparing to the base case (Eigenanalysis base case.xls).

    Spectra of injected rectangular-wave disturbances in cases F_6_n (n = 1, 2, or 3) consist of only odd harmonics and the frequency of the first harmonic is shown in third column of the above table.

    As an example, here are the details of the cases F_5_2, F_6_2.

    Case # Type of injected signal Frequency of first harmonic/Hz Source location Description
    FM_1 Sinusoidal 0.86 4 Resonance with local 0.86Hz mode
    FM_3 Sinusoidal 0.37 77 Resonance with inter-area 0.37Hz mode
    FM_6_2 Periodic, rectangular 0.2 79 Spectra of forced harmonics consist of 0.2Hz, 0.6Hz, 1Hz, 1.4Hz, etc modes
    FM_7_1 Sinusoidal 0.65
    0.43    		 79
    118    		 Two sources of forced signals creating resonance with two different modes, respectively

    Each case of forced oscillations from the above table has only one generator with periodic signal injected into its governor. The model of each generator remains classical.

    The forced signal for each case is modeled by individual User Defined Model (UDM) implemented in TSAT software. The structure and parameters of each UDM can be found in corresponding block-diagram. Common element for each UDM is the block BLK, Steam turbine. That is the “Governor End Block Type T4” in TSAT with the following parameters: T4=0.5; T5=T6=T7=0; Pmax=1.0; K2=1; K2=K3=K4=K6=K7=K8=K9=0; LPBUS=0.